The outstanding new psychological thriller from the 5 million copy-bestselling author of Here to Stay and The Magpies 'The plot swerves in an entirely unpredictable direction , providing an intriguing mystery that turns on their mentor's work on the behaviour of psychopaths' Sunday Times ‘I loved this... So clever and fresh with a wild and incredibly satisfying twist’ Lisa Jewell 'I devoured it in two compulsive sittings. 'Gripped' doesn't even come close!!' Marian Keyes 'A fast-paced thriller, full of twists upon twists. Hugely enjoyable' Alex Michaelides 'Twisty, clever, often funny, always inventive' Elly Griffiths -- Summer 1999. Will joins five other idealistic graduates working for an eccentric psychology professor. They’re going to launch a website to change online dating forever. No-one expects it to end in tragedy. Twenty-five years later, Will gets an invitation: a dinner party. A chance to see the old gang again. But as soon as he arrives, something doesn’t seem right.